I have just discovered that if I put a "NameVirtualHost *:80" statement in default-server.conf the error message goes away and I can then access site 1 and site 2. I cannot access the host server index page, that still returns site 1s home page. I haven't had time today to add any other sites.

Using the server ip I would expect to see the host index page if ispconfig was not present.

If that is correct behaviour than it is no big deal but how do I identify site 1. Is it by lowest ClientID, WebID, alphabetical URL name or what?.

The main site is www.example.tld and the server is host.example.tld. There are (should be!) a dozen or so other hosted sites of lower priority (they don't pay much rent)